There's been one problem I've had since I installed Ubuntu to run alongside Windows, I assume this would also be the same if it was installed to replace the other operating system as well, the installer prompts you to create a password upon typing in the user account name and if you don't put in a password and just put in the user account name, it ends up saying to create a password. My comparison is in Windows and Mac OS X, you are never forced to create a password.
If you remove the password on your Admin account in System Settings > User Accounts, you won't be able to authenticate whenever you try to install something, because it requests for a password and putting in no password at all isn't going to work, it will just act as if you put in an invalid password. This is what I call "getting locked out of privileges".
I'm finding the "Authenticate" window that comes up whenever you install something or accessing somewhere a nuisance, 'cause it always requests for your password.
So my question is - Why does Ubuntu force users to create a password upon installation?